Description The Optimistic Duration field contains the best-case possibility for the total span of active working time expected for a task, that is, the amount of time from the optimistic start to the optimistic finish of a task. You can enter the optimistic duration as part of a PERT analysis calculation, which takes a weighted average of expected, pessimistic, and optimistic dates and durations, or you can have Microsoft Office Project calculate it for you. This field is available only in the PA_Optimistic Case table or the PA_Optimistic Gantt view.

How Calculated When you first create a task, the Optimistic Duration field contains "0 days." When you enter optimistic start and finish dates, and then click Calculate PERT
on the PERT Analysis toolbar, a probable best-case duration is calculated and placed in the Optimistic Duration field.

Best Uses Use the Optimistic Duration field in the PA_Optimistic Case table or the PA_Optimistic Gantt view to estimate the probabilities of task dates. By default, the PERT analysis calculation gives heaviest weight (4) to the expected information, and the lightest weight (1 each) to the pessimistic and optimistic information.

Example You have several critical tasks for which you want to see the best-case, worst-case, and expected durations. You enter the expected start and finish dates for these tasks, as well as their optimistic and pessimistic start and finish dates, and then run the PERT analysis calculation.

Remarks By changing the weight that Project attributes to each of the three estimated durations, you can tailor the probable estimate to be more accurate. To change the weight, click PERT Weights
on the PERT Analysis toolbar, and then alter the default settings.

The Optimistic Duration field uses the Duration1 custom duration field.